Fixture for use with magnetic chucks.



S. KARASICK.

FIXTURE FOR USE WITH MAGNETIC CHUCKS.

APPLICATION FILED MAR. 28, I917.

Patented Apr. 22, 1919.

1 r1 II/I/IIIIII/II UNITED STATES PATENT OFFICE.

SAMUEL KARASICK, OF NEW YORK, N. Y., ASSIGNOR TO THE KAR ENGINEERING COMPANY, CF NEW YORK, N. Y., A CORPORATION OF CONNECTICUT.

Specification of Letters Patent.

Patented Apr. 22, 1919.

Application filed March 28, 1917. Serial No. 158,079.

To all whom it may concern:

Be it known that I, SAMUEL KARAsmK, a citizen of the United States, and a resident of the city of New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Fixtures for Use with Magnetic Chucks, of which the following is a specification.

This invention relates broadly to small tools particularly adapted for use with magnetic chucks.

The principal object of the present invention comprises the forming of small tools or fixtures of individual units composed of materials adapted to be magnetized, whereby the magnetism from the poles of an electric chuck may be transmitted through the individual unit sections and attracted thereby securing to the sections iron or steel work upon which operations are to be performed.

More specifically the object of the present invention is to construct fixtures in the nature of parallel bars, V-blocks, angle irons, etc., by securing together alternate laminations of soft iron or soft steel plates and Babbitt metal, copper, or other nonmagnetic sheets and securing these sheets together to form a complete fixture which when set on the face of a magnetic chuck will transmit the magnetism from the chuck through the fixture to secure work in position upon the fixture.

It is equally a primary object of the present invention to provide fixtures of the character above specified which are capable of being positioned upon the face of a magnetic chuck without particular reference to the relation of the poles of the chuck to the fixture.

Other and further objects of the present invention will in part be obvious and will in part be pointed out hereinafter in the specification following by reference to the accompanying drawings forming a part of the specification and wherein like parts are represented by like numerals throughout the several figures thereof.

Figure 1 shows an angle iron constructed in accordance with the present invention.

Fig. 2 illustrates a parallel bar in accordance with the present invention.

Fig. 3 shows a V-block in accordance with the present invention.

Fig. 4 is a diagrammatic view illustrating the magnetic condition of a parallel bar in accordance with the present invention when a plurality of the sections of the bar overlap a slngle pole in the face of the chuck. Big. 5 1s a diagrammatic View illustrating the magnetic condition of a parallel bar in accordance with this invention where the bar extends between energized magnetic poles of opposite polarity. Fig. 6 is a sectional detail view illustrating one form of construction whereby the non-magnetic material, such as Babbitt metal, comprises the binder for securing the parts together.

Fig. 7 is an end view of Fig. 6.

Fig. 8 illustrates another form wherein the parts are secured together by non-mag netic rods of brass or other material.

For certain types of grinding and other machine tool work magnetic chucks are best adapted to secure the work to the bed of the machine to enable the cutter or grindlng wheel to engage and operate upon the woi k. Obviously magneti chucks can only act directly upon work capable of being magnetized and usually magnetic chucks are used with work which directly engages the face of the chuck. Where the chuck face is flat it is usual to operate only on flat pieces of work. Difliculty has been encountered in the attempt to use magnetic chucks with irregularly shaped work that cannot be brought into intimate contact with the face of the chuck. The reason for this is because sufficient magnetic and frictional resistance cannot be set up between the chuck face and the work in order to securely hold the work. Where magnetic chucks are used with irregularly shaped pieces heretofore it has been the custom to place angle irons or parallel bars on the face of the chuck. The magnetism in the chuck obviously retains the angle irons or parallel bars securely in position on the chuck face and then the Work is clamped in position on the fixtures which are held by the chuck. The reason the ordinary angle iron or parallel bar will not hold work is because the bar or angle iron being a continuous piece of magnetic material forms a, substantially complete conductor for the magnetic lines and the lines of force do not leave the ordinary angle iron or bar so that a piece of work laid thereon will not be securely held. The

clamping operation obviates one of the most advantageous features in the chuck, namely, its ready adaptability to quick adjustment of work.

, The present invention comprises angle irons, parallel bars, V-blocks, and etc., of standard shop practice constructed of alternate laminations of magnetic materials, such as soft iron or soft steel, and non-magnetic :material, such as Babbitt metal or copper.

Parallel bars, angle irons, or V-blocks of this type when placed upon the face of an electric chuck transmit a considerable amount of the magnetic lines directly to the faces of these fixtures so that where a soft iron or soft steel work piece is placed against a face of such fixture the magnetic. lines enter the work piece and'thereby secure the work in position against the fixture without necessity of clamping. The laminations in these structures are preferably in excess to the number of poles on the ordinary magnetic chuck face, and therefore the fixtures may be positioned generally over the chuck face without particular-reference to the relation between the laminations in the fixture and the pole pieces in the face of the chuck.

Referring now to the drawings the fixtures are made up of sections 1 of magnetic material such as soft iron or soft steel arranged in alternation with spacers 2 or sections of non-magnetic material, such as Babbitt metal, lead, copper, fiber, and etc., so

that magnetic lines entering one block of magnetic material 1 will necessarily encounter and pass over or through a zone of nonmagnetic material before the lines enter the next and adjacent block of magnetic material. By this construction the magnetic lines of force do not fiow direct-1y through thefixture from one end to the other but a large number of lines of force flow through the air and around each separator of nonmagnetic material. These lines flowing through theair are obviously useful in and 'capable of securing 1IOI1 or steel work to the surfaces of the fixtures, as is illustrated in dotted lines as at A Fig. 1 and in dotted lines as at B Fig. 3.

Figs. 4 and 5 illustrate more particularly the zones of action between various sections of a fixture in accordance with the present invention when in position on the face of a chuck, and Fig. 4 shows more particularly the lines of force passing through an object O shown in dotted lines where a plurality of sections of the fixture overlap the single poles in the magnetic chuck 4. Fig. 5 illustrates the action where a parallel bar in accordance with the present invention extends between energizing poles of opposite polarity and shows lines. of force flowing through the air at each spacer plate 2. Fig. 6 illus trates one form of securing the magnetic plates together by means of Babbitt or lead composing the spacing member 2 and comprises more particularly the provision of holes through each magnetic plate, the ends of said holes being counter-bored. These plates are then set in position and Babbitt poured between the plates to form spacer plates 2 which are connected by junction members 5 thereby forming a continuous interlocking structure whereby the entire fixture is rigidly secured together. In order to obviate rotation of the magnetic elements 1 around the junction members or bars 5 it may be desirable to. provide projections 6 of Babbitt which extend into suitable depressions formed in the section 1, or vice versa. In Fig. 8 is illustratedanother manner of connecting the laminations together and in this figure the magnetic plates 1 and the spacer plates 2 are drilled and threaded upon brass'rods 7 which may be upset or riveted at their ends thereby securing-the various parts together.

It is to be understood that the magnetic elements of applicants fixtures are not intended to possess any inherent magnetism but are formed of soft iron or soft steel and merely comprise pathways for the magnetic lines of force extending from the pole pieces of an energized magnetic chuck, and it is also to be understood that prior to the energizing of the magnetic chuck these fixtures may be freely movable over the face of the chuck and be positioned in any suitable position thereon without particular reference to the relation of the pole pieces of the chuck to the laminations of the fixtures.

Having thus described my invention what I claim is l. A work-supporting fixture for use with a magnetic chuck, comprising, incombination with said chuck, unitary work-supporting member formed of alternate magnetic and non-magnetic plates composing magnetic sections exceeding the number of poles in the face of the chuck, said member being freely movable in all directions over the chuck face and maintainable in all predetermined positions on said chuck face solely by the energizing of the magnetic chuck.

2. A work-supporting fixture for use with a magnetic chuck, comprising, in combination with said chuck, a separable unitary work-supporting member formed of alternate magnetic and non-magnetic plates composing magnetic sections exceeding the number of poles in the face of the chuck, said member being freely movable in all directions over the chuckface and maintainable in all predetermined positions on said chuck face solely by the energizing of the magnetic chuck.

3. A work-supporting fixture for use with a magnetic chuck, comprising, in combination with said chuck, a unitary work-supporting member formed' of alternate magnetic and non-magnetic plates com osin magnetic sections exceeding the num er les in the face of the chuck, said member o er the chuck face and maintainable-in all predetermined positions on said chuck face solel by the energizing of the magnetic chuc v .v a

4. A work-supporting fixture for use with a magnetic chuc comprising, in combination with'Tsaid chuck, a separable unitary Work-supporting member formed of altermagnetic chuck; v p 5. A work-sup ortingfixture for use with nate magnetic and non-magnetic plates comosin magnetic sections exceedin the num-' r0 ;poles in the face of the c uck, said chuck face solely a magnetic chuc comprising in combina? porting member formed of alternate laminations of magnetic and non-magnetic material composing magnetic sections exceeding the "number of pole pieces of the chuck,

said fixture member 'being positioned and held in all predetermined positions upon the chuck face without reference to the rela- I a magnetic chuc mg slidingly movable. in all directions netic material com osin tion of. the laminations and the pole pieces of the chuck when the latter is energized.

6. A work-supfiortingfixture for use with comprising, in combination with said chuck, a unitary work-sup- 'porting member formed of alternate laminations of magnetic and non-magnetic material composing magnetic sections exceeding the number of pole pieces of the chuck,

-' and freely movable in all directions over the being .positioned and held in all predetermined posichuck face, said fixture member tions upon the chuck face without reference 7. A'work-supgorting fixture for use with a. magnetic chuc comprising, in combination with said chuck,;a separable unitary vwork-supporting member formed ,of alterby the energizing of the nate laminations of magnetic'and non-magmagnetic ,sections exceeding the num er 0 pole pieces ofthe chuck, and freely movable in all directions tion with, said chuck, a unitary woik-supover the chuck face, said fixture member being' positioned and held in all predetermined positions upon the chuck face withoutreference to the relation of the laminations and SAMUEL KARASICK.

to the relation of the laminations and the pole pieces of the chuck when the latter is energized. 

